|
As callus from Canavalia lineata L. (DC) was treated in pH8 buffer solution for one hour, arginase activity in its cell free extracts was twice higher than in pH 6. From the cell free extracts, two forms of arginase, heavy and light, were appeared in Sephacryl S-200 gel filtration. One form of arginase (heavy form) was estimated in 380 kD and another form (light form) was 179 kD in Sephacryle S-300 column chromatography. The heavy form at pH 8 and light form at pH 6 were predominant, respectively. However, even at pH 6 the heavy form was mainly appeared by the addition of 0.5 mM Mn^2+ in the cellus floating solution. And the light form from the column was easily transformed into the heavy form in pH 8. Arginase activity of light form was increased to about same value of heavy form by the incubation with Mn^2+ for 30 min in vitro, but heavy form did not showed any increasment in its cataltic activity with additional Mn^2+. In condition of Mn^2+ free assay system, K_m and V_max was estimated in 22 mM and 1.61 μmole urea·min^-1·mg^-1 protein of heavy form, and 30 mM and 0.79 μmole urea·min^-1·mg^-1 protein of light form at pH 9.7.
|